This is part Seven of the continuing series on two-filter document culling. This is very important to successful, economical document review. Please read parts onetwothreefourfive and six before this one.

First Filter – Other MultiModal Culling

There are many other bulk coding techniques that can be used in the first filter stage. This is not intended to be an exhaustive search. Like all complex tasks in the law, simple black letter rules are for amateurs. The law, which mirrors the real world, does not work like that. The same holds true for legal search. There may be many Gilbert’s for search books and articles, but they are just 1L types. For  true legal search professionals they are mere starting points. Use my culling advice here in the same manner. Use your own judgment to mix and match the right kind of culling tools for the particular case and data encountered. Every project is slightly different, even in the world of repeat litigation, like employment law disputes where I currently spend much of my time.

Legal search is at core a heuristic activity, but one that should be informed by science and technology. The knowledge triangle is a key concept for today’s effective e-Discovery Team. Although e-Discovery Teams should be led by attorneys skilled in evidence discovery, they should include scientists and engineers in some way. Effective team leaders should be able to understand and communicate with technology experts and information scientists. That does not mean all e-discovery lawyers need to become engineers and scientists too. That effort would likely diminish your legal skills based on the time demands involved. It just means you should know enough to work with these experts. That includes the ability to see through the vendor sales propaganda, and to incorporate the knowledge of the bona fide experts into your legal work

One culling method that many overlook is file size. Some collections have thousands of very small files, just a few bits, that are nothing but backgrounds, tiny images, or just plain empty space. They are too small to have any relevant information. Still, you need to be cautious and look out for very small emails, for instance, ones that just says “yes.” Depending on context it could be relevant and important. But for most other types of very small files, there is little risk. You can go ahead a bulk code them irrelevant and filter them out.

Even more subtle is filtering out files based on their being very large. Sort your files by size, and then look at both ends, small and big. They may reveal certain files and file types that could not possibly be relevant. There is one more characteristic of big files that you should consider. Many of them have millions of lines of text. Big files are confusing to machine learning when, as typical, only a few lines of the text are relevant, and the rest are just noise. That is another reason to filter them out, perhaps not entirely, but for special treatment and review outside of predictive coding. In other projects where you have many large files like that, and you need the help of AI ranking, you may want to hold them in reserve. You may only want to throw them into the ranking mix after your AI algorithms have acquired a pretty good idea of what you are looking for. A maturely trained system is better able to handle big noisy files.

File type is a well-known and often highly effective method to exclude large numbers of files of a same type after only looking at a few of them. For instance, there may be database files automatically generated, all of the same type. You look at a few to verify these databases could not possibly be relevant to your case, and then you bulk code them all irrelevant. There are many types of files like that in some data sets. The First Filter is all about being a smart gatekeeper.

File type is also used to eliminate, or at least divert, non-text files, such as audio files or most graphics. Since most Second Filter culling is going to be based on text analytics of some kind, there is no point for anything other than files with text to go into that filter. In some cases, and some datasets, this may mean bulk coding them all irrelevant. This might happen, for instance, where you know that no music or other audio files, including voice messages, could possibly be relevant. We also see this commonly where we know that photographs and other images could not possibly be relevant. Exclude them from the review database.

You must, however, be careful with all such gatekeeper activities, and never do bulk coding without some judgmental sampling first. Large unknown data collections can always contain a few unexpected surprises, no matter how many document reviews you have done before. Be cautious. Look before you leap. Skim a few of the ESI file types you are about to bulk code as irrelevant.

This directive applies to all First Filter activities. Never do it blind on just logic or principle alone. Get you hands in the digital mud. Do not over-delegate all of the dirty work to others. Do not rely too much on your contract review lawyers and vendors, especially when it comes to search. Look at the documents yourself and do not just rely on high level summaries. Every real trial lawyer knows the importance of that. The devil is always in the details. This is especially true when you are doing judgmental search. The client wants your judgment, not that of a less qualified associate, paralegal, or minimum wage contract review lawyer. Good lawyers remain hands-on, to some extent. They know the details, but are also comfortable with appropriate delegation to trained team members.

There is a constant danger of too much delegation in big data review. The lawyer signing the Rule 26(g) statement has a legal and ethical duty to closely supervise document review done in response to a request for production. That means you cannot just hire a vendor to do that, although you can hire outside counsel with special expertise in the field.